The Centre for Health Protection (CHP) of the Department of Health today (September 28) reported the latest number of cases of dengue fever (DF), and again urged the public to maintain strict environmental hygiene, mosquito control and personal protective measures both locally and during travel.

From September 21 to 27, the CHP recorded one imported DF case. The patient had been to the Philippines during the incubation period.

As of yesterday (September 27), 109 cases had been confirmed this year, 29 of which were local cases and 80 imported cases. The imported cases were mainly imported from Thailand (30), the Philippines (15) and Cambodia (nine). Since September 4, the number of local DF cases recorded this year has remained at 29.

DF remains endemic in some areas in Asia and beyond. In Guangdong, there were 378 cases recorded in the first eight months of this year. The latest figures for 2018 reveal that 2 087 cases have been recorded in Singapore (since December 31, 2017) and 126 in Japan. In Taiwan, 134 local cases have been recorded to date in 2018. In the Americas, the latest figures indicate that 32 744 cases have been filed in Mexico in 2018.

The public should take heed of the following advice on mosquito control:

Completely change the water of flowers and plants at least once a week. The use of saucers should be avoided if possible;

Level irregular ground surfaces before the rainy season;

Avoid staying in shrubby areas; and

Take personal protective measures such as wearing light-coloured long-sleeved clothes and trousers and apply insect repellent containing DEET to clothing or uncovered areas of the body when doing outdoor activities.

To reduce the risk of infections spread by mosquitoes, apart from general measures, travellers returning from affected areas should apply insect repellent for 14 days (DF) or at least 21 days (Zika virus infection) upon arrival in Hong Kong. If feeling unwell, seek medical advice promptly and provide travel details to the doctor. DEET-containing insect repellents are effective and the public should take heed of the tips below:

Read the label instructions carefully first;

Apply right before entering an area with risk of mosquito bites;

Apply on exposed skin and clothing;

Use DEET of up to 30 per cent for pregnant women and up to 10 per cent for children*;

Apply sunscreen first, then insect repellent; and

Re-apply only when needed and follow the instructions.

* For children who travel to countries or areas where mosquito-borne diseases are endemic or epidemic and where exposure is likely, those aged 2 months or above can use DEET-containing insect repellents with a DEET concentration of up to 30 per cent.